Apparatus for screening out secondary x-rays with a continuously moved grid



Nov. 29, 1938. E. oTvbs APPARATUS FOR SCREENING OUT SECONDARY X-RAYS WITH A CONTINUOUSLY MOVED GRID Filed March 17, 1937 Patented Nov. 29, 1938 v UNITED STATES PATENT OFFICE APPARATUS FOR SCREENING OUT SECOND- ARY X-RAYS WITH A CONTINUOUSLY MOVED GRID Ervin fitviis, Budapest, Hungary Application March 17, 1937, Serial No. 131,509 In Hungary March 19, 1936 3 Claims. (Cl. 25062) The present invention relates to an X-ray aptheir stroke, the lower one moving to the right paratus having a bucky diaphragm reciprocated (Fig. 2) the segment 8 disengages from the upper by a driving mechanism. toothed rod and engages the lower one, so that One object of the invention is to move the the direction of movement is suddenly reversed. bucky reciprocating diaphragm in such a way The driving mechanism may be constructed 5 that during an exposure of any length, the proa so n s a Way that the segment first duction of undesirable shadow lines is avoided. engages from one of the toothed rods and then Another object of the invention is to increase engages the other one, it is, however, preferable the bucky effect by employing a special multiple to efifect the engagement one moment prior to 10 diaphragm. the release from the other toothed rod. The rel- 10 These objects are attained by reciprocating the ative movement between the rods 6 and 1 necesdiaphragms along the whole length of their paths sary for this mode of operation is afforded by with uniform speed and at the ends of their paths the fle ty 0f t e spring The toothed reversing their direction of movement very sud- 6 is rigidly fastened o t grid, b t t y be 1 denly, so that objectionable shadow lines are not also shiftably arr developed. The invention also relates to a drivy m s of th s bed mechanism the grids ing mechanism adapted to move one or more are moved with uniform speed and at the end diaphragms in this manner; if two or more dia,- of their path their movement is reversed so sudphragms are moved in this Way closely and paraldenly that an de b e d image is not p lo] to one another, the bucky effect is increased duc d. The ri s may b arra v ry closely greatly beyond the results heretofore obtained. adjacent to one another.

The accompanying drawing shows one pre- The shape and arrangement of the laminations ferred embodiment of a double diaphragm and of g e length of stroke of grids aind the of the driving mechanism according to the insp d of m vemen may be chosen at wil vention. I claim: 25

Fig. 1 is a front elevation of the apparatus in 1- I n X-r y ppar a bu y diaphragm, the central position of the grids and Fig. 2 shows a b 0f toothed 10ds secured to said diaphragm, the driving mechanism in one of its extreme pod a C uo y tat ot segment s sitions. Figs. 3 and 4 are side elevations of the uated b tw n aid hed rods n n i grid. them alternately for reciprocating said dia- 30 The parallel grids l and 2 are moved in guides Dhragm at uniform speed and for suddenly 9 along even paths, but they may be moved along versing its direction. at the ends of its path. curved paths too. Each grid is provided with 2. In all y pp a blleky phrag toothed rods 3 arranged lengthwise in the direca pa r Of oothed s ecured to said d aphra tion of movement of the grids. The pair f spring means connecting said toothed rods per- 35 toothed rods at each side of the grids engage a mitting relative displacement of the latter and freely rotatable, but not shiftable gear 4. Thus, a continuously rotating toothed me i ed when one of the grids is moved, its motion is etw n s toothed r s d n in them transmitted to the other grid and both are caused alternately r reciprocating s ph m a 40 to move always with equal speeds in. opposed uniform speed and for suddenly reversing its 40 directions. direction of movement.

One of the grids, for instance, the lower one, In an y pp t tWO substantially is provided with a laminated spring 5, which is parallel b ieky diaD- s S d lose to One disposed perpendicularly to the plane of the grid another, a pair of toothed rods secured to one on one side of same. On this spring are fastened said diaphmgms, a Continuously Ot 45 two toothed rods 6 and 1 extending parallel to toothed segment situated between said toothed the direction of movement of the grids and which rods nd e in th m alternately r r c pr cooperate with a toothed segment 8. This segng one of said diaph at uniform peed ment is uniformly rotated for example by the aid and for suddenly reversing 'its direction at the of an electric mgtor and in case the direction ends Of 1175 path, and means fOI moving the other 50 of rotation corresponds to the arrow of the drawof the said two d p gms with the same speed ing, when the segment is in engagement with the as the first mentioned diaphragm, but in an D- upper toothed rod 6, the grid 2 is moved to the Posed direetionright (Fig. 1). When the grids have finished ERVIN O'I'VOS. 

